1. Field of the Invention
The field of the invention is devices attached to dental x-ray unit machines extension tubes to more accurately locate the x-ray pattern upon a patient's face.
2. Description of the Related Art
In the field of dentistry, it often becomes necessary for the dentist or technician to take x-rays of a portion or all of a patient's teeth for purposes of determining dental carries, misalignment of teeth, problems with teeth roots, and for other reasons. This is commonly accomplished by the placement of x-ray sensitive film within the patient's mouth and interiorly to the teeth. Most often, the film is held in place for the x-ray procedure by the patient clamping their teeth down upon a perpendicularly protruding paper tab centrally located on the flat side of the film. The x-ray unit machine emitting head is placed proximate the patient's jaw immediately outside the skin overlying the location of the film.
Dental x-ray units are conventionally equipped with extension tubes to be used as guides in establishing the direction of the x-ray beam pattern conically ejected by an emitter situated in the x-ray unit head. Generally the x-ray emitter is situated proximate the point of attachment of the extension tube to the x-ray unit head.
It is not uncommon for the operator to misdirect or misalign the x-ray beam when accomplishing x-ray procedures in which case only a portion of the film is exposed to the x-rays (and thus not all teeth filmed). In such case, the operator must perform the x-ray procedures again. This is not only costly in terms of film used but also subjects the patient to repeated doses of x-rays. Further, the operator may not know that the film was not properly exposed until after it is developed, which may be a period of time after the procedure was done. This necessitates repeating the procedure with its attendant duties at a later time, making for inefficient expenditure of time and at an increased cost.
While the operator generally has no difficulty knowing where on the face of the patient the film is situated within the month, yet it would be an obvious great help to the operator if they knew the extent of the x-ray beam pattern.
There are various devices which are known to the Applicant for accomplishing the alignment of dental x-ray unit heads and some are as follows. Nelsen, in U.S. Pat. No. 2,581,431, adds an additional tubular extension to the supplied extension tube and in this tubular extension, places cross hairs at its terminal end together with a string situated along the longitudinal center. Then the terminal end of the device is placed proximate the patient's face. By sighting along the string, the path of the x-rays is determined. Seidenberg, in U.S. Pat. No. 4,887,286, discloses a device which attaches to the extension tube of the dental x-ray unit, the device utilizing an upper and a lower light emitting unit to project two beams of light outwardly defining the beam. The light emitting units are pre-focused bulbs which may include an integral lens. The device is so constructed so that the light emitting units are located within the extension tube and potentially in the path of the x-ray beam although by being on the top and bottom, they would interrupt the beam such that the exposure of tooth roots would be affected.
Burnham, in U.S. Pat. No. 2,659,824, situates a pair of focused light beam sources on opposite sides of the dental x-ray unit head such that the coincidence of the two light beams indicate the center of the x-ray beam. Lastly, Updegrave, in U.S. Pat. No. 3,745,344, discloses a lead-lined rectangular collimating tube attached to the dental x-ray unit head which in turn has attached at its terminal end a bite block. Alignment is achieved since the patient moves to a correct position to utilize the bite block.
While the above devices shown in the patents cited apparently accomplish the purpose intended, yet all have shortcomings of one type or another, either being bulky, difficult to use, or as in the case of Seidenberg, have the potential of being in the path of the x-ray beam.
It is readily apparent therefore that improvements to the art of dental x-ray alignment devices are needed inasmuch as with all the devices which are known and available, yet they have not been adopted in widespread use.
Accordingly, there is a need for a simple and inexpensive device which efficiently and readily aligns the x-ray beam pattern upon the face of the patient in order that the operator may be absolutely sure that the x-ray beam is correctly aimed to fully expose the entire film.